Reticle for variable power telescope sights



July 16, 1963 G. R. SHAW 3,097,432 RETICLE FOR VARIABLE POWER TELESCOPESIGHTS Filed Oct. 24, 1960 Geo/ye R J/MP'W INVENTOR.

w (it ATTORNEY 3,fi97,432 Patented July 16, 1963 3,097,432 RETIGLE FGRVARIABLE POWER TELESCOPE SIGHTS George R. Shaw, El Paso, Tex, assignorto Wiiliam R. Weaver, El Pasc, Tex. Filed Oct. 24, 196i), Ser. No.64,364 2 Claims. (Cl. 33-50) This invention relates to reticles fortelescopic sights for firearms, and more particularly to a reticleespecially adapted for a variable power telescopic sight.

As is well-known, in variable power telescopes, changes in magnificationchange the apparent size of the reticle just as it changes the size ofthe image of the target. For example, where the reticle is of theconventional crosshair design, as the power is developed,the apparentthickness of the lines defining the reticle is also developed. Suchthickening of the reticle lines serves to obstruct the target andprevent accurate aiming. These undesirable conditions are well-known tothose skilled in the art.

Accordingly, it is a primary object of the present invention to providean improved reticle design which will obviate the disadvantagesresulting from increases in the magnification of the reticle by increasein the power of the scope.

In accordance with the present invention, a preferred design is areticle disk of flat transparent character which carries on one sideaiming indicia which comprises a pair of lines defining the main crosslines which project toward a point of intersection at the center of thereticle disk. The main cross lines, however, terminate at or adjacent atiny circle concentric about the center of the reticle disk, this centercorresponding to what would be the point of intersection of the maincross lines if the latter extended across the circle. Inside the centercircle is a second pair of cross lines intersecting on the common centerand radially aligned with the main cross lines. These second cross linesare made to have a line thickness very much less than that of the maincross lines. As a result, when the reticle is viewed at the lowest powerof the scope, the center circle may correspond substantially to a tinydot such as is frequently provided at the intersection of the usualcrosshairs, or as an extremely small but definite circle in which theinterior cross lines are, however, so fine as to be practicallyinvisible at the lowest power of the scope. As the power of the scope isincreased, the area of the small center circle will appear to increasein proportion to the increase in power, as will the interior crosslines, these appearing to become increasingly heavier until the maximumpower of the scope is attained, at which point they will appear to be ofabout the same thickness as that of the main cross lines at the lowestpower. Due to the magnification, the center circle will have appeared toexpand so as to occupy a substantially increased proportion of thevisible area of the reticle disk. In other Words, as the power isincreased, the center cross lines and their intersection become theprimary aiming ele ments, while the outer or main cross lines, now alsoof increased thickness, will serve to help direct the eye of the usertoward the center.

In accordance with a preferred embodiment of this invention, the maincross lines and the small inner circle will be defined by lines having athickness such as to subtend about 0.6 minute of angle on the target,while the cross lines inside the center circle will be made to athickness ranging from about 25% to 50% of the actual thickness of themain cross lines. A preferred thickness for these lines will be about0.24 minute of angle. The center circle, as indicated, will be made verysmall but to a specific relation to the amount of target coverage it isdesired to provide. For example, the center circle may have a diametersuch as to subtend an angle of from about 8 to 20 minutes. One usefuldiameter will be such as to cover about 10 minutes of angle or about 10inches at yards from the scope, with the circular line itself, asindicated, having an actual thickness such that it subtends about 0.6minute of angle.

Other and more specific objects and advantages of this invention willbecome apparent from the following de tailed description of thisinvention when read in conjunction with the accompanying drawing whichillustrates one useful embodiment in accordance with this invention.

In the drawing:

FIG. -1 is a greatly enlarged view of a reticle disk having markedthereon indicia of the design or pattern in accordance with thepreferred embodiment of this invention, the various lines being greatlyexaggerated for purposes of illustration;

FIG. 2 is a view similar to shown on a somewhat smaller located on atarget; and

FIG. 3 is a view similar to 'FIG. 2, showing the relative dimensions ofthe indicia of the reticle at a magnification higher than that of FIG.2.

Referring to the drawing, the reticle comprises a disk 10 constructed ofany suitable transparent material, such as glass, the disk being of theusual fiat or plane form. It will be understood that the reticle diskwill be adapted for mounting in any suitable or conventional manner inthe barrel of a variable power telescope sight. Carried on one face ofthe disk are indicia, designated generally by the numeral 11, definingthe desired reticle pattern. These indicia may be applied to the reticledisk by any of the conventional methods, such as etching, printing,photographic methods, or by deposition of metal, all methods understoodby those skilled in the art.

The indicia 11 comprise a pair of main cross lines 12-12 arranged on thedisk at right angles to each other to intersect at the center of thedisk. These lines, however, terminate at or near a small circle 13concentrically positioned about the center 14 which would normallyconstitute the intersection of lines 12- 12 except for the inter ruptionof lines 1212 at the line defining circle 13. A second pair of crosslines 15-45 are marked on the disk inside circle 13 to intersect oncenter 14 and are disposed in radial alignment with lines 1212.

Cross lines 15+15 are made to have a natural thickness considerably lessthan the natural thickness of the main cross lines =1l2l2, and thethickness of lines d5-15 is also made less than that of the linedefining circle 13. The latter will usually have the same line thicknessas lines -1212.

By Way of example as to the relative thicknesses of the various lines,lines 12-12 have a natural thickness such that they cover about 0.6minute of angle at 100 yards. The line defining circle 13 will havesubstantially the same thickness. Lines 15-45 will have a thicknessgenerally ranging from about 25 to 50% of that of lines 12-12, and inthe preferred embodiment will be about 40% of that of lines 12412.

Circle 13 will have a diameter such as to subtend a selected angle. Inan exemplary embodiment, the diameter of circle 13 will be such that itwill cover about 10 inches at 100 yards.

When a reticle of the kind described is installed in a telescopic sighthaving a variable magnification from, say, 2 /2 x to 8X, the circle 13,until magnified, may be of a size such as to compare closely to the dotwhich is afiixed to the intersection of the crosshairs of reticlescommonly known as dot reticles or may be of a slightly larger size suchas will provide a very small circle or sighting aperture in which theaiming point on the target will be framed. Cross lines 15-45 will bepractically invisible at the lowest power. The small center circle andthe main cross FIG. I, the reticle being scale than in FIG. 1 and lines12-12 will then serve, at the lower powers, as the principal aimingelements for directing the eye of the user to the center of the reticleand on to the target. As the power of the sight is increased, thediameter of circle 13 will increase proportionately as will the apparentweight or thickness of lines 15, as illustrated in FIG. 3. At maximumpower, lines 15 will approach the apparent weight of lines 12-12 at lowpower and will thus stand out more prominently and with theirintersection will become the primary sighting elements of the reticle.By reason of the increased diameter of circle 13 at the magnification,the latter will, for all practical purposes, become the main sightingarea of the reticle. Lines 12-42, which will, of course, also increasein thickness by reason of the magnification, Will, however, continue toserve to direct the eye of the user toward the central sighting elementsand to that extent, will continue to serve their normal sighting:function.

It will be seen that by making the internal cross lines 15 much lighteror finer than the main cross line 12, the former will, at dull power,provide minimum obstruction to sighting of the target, since at themaximum power they will have attained substantially only the originalthickness of the main cross lines.

It will be evident that lines 15-15 may be considered as portions oflines 12-42. lying within circle 13, these inner portions being ofnatural lighter weight or thickness than the outer portions which aredesignated as lines 12-12.

It will be understood that various changes and modifications may be madein the details of the illustrative embodiment within the scope of theappended claims, but Without departing from the spirit of thisinvention.

What I claim and desire to secure by Letters Patent is:

1. A reticle for variable power telescope sights, comprising, atransparent disk having a circular area defining substantially the fullfield of view of said sight, indicia carried on one surface of the disk,said indicia comprising a pair of main CIOSs lines disposed to intersectat the center of said area and extending to the periphery of said area,the point of intersection of said main cross lines being enclosed by aline defining a circle having an area which is relatively minute withrespect to the area of said disk, said circle having an inside diameterto subtend an angle of from about 8 to about 20 minutes, the portions ofsaid cross lines lying within said circle having a natural linethickness of from about 25% to about of that of the lines outside saidcircle.

2. A reticle according to claim 1 wherein the natural thickness or theportions of the main cross lines lying outside said circle and of theline defining said circle is such as to subtend about 0.6 minute ofangle, and the natural thickness of the portions of said cross linesinside said circle is such as to subtend about 0.24 minute of angle.

Beniord July 30, 1957 Sullivan Sept. 17, 1957

1. A RETICLE FOR VARIABLE POWER TELESCOPE SIGHTS, COMPRISING, ATRANSPARENT DISK HAVING CIRCULAR AREA DEFINING SUBSTANTIALLY THE FULLFIELD OF VIEW OF SAID SIGHT, INDICIA CARRIED ON ONE SURFACE OF THE DISK,SAID INDICIA COMPRISING A PAIR OF MAIN CROSS LINES DISPOSED TO INTERSECTAT THE CENTER OF SAID AREA AND EXTENDING TO THE PERIPHERY OF SAID AREATHE POINT OF INTERSECTION OF SAID MAIN CROSS LINES BEING ENCLOSED BY ALINE DEFINING A CIRCLE HAVING AN AREA WHICH IS RELATIVELY MINUTE WITHRESPECT TO THE AREA OF SAID DISK SAID CIRCLE HAVING AN INSIDE DIAMETERTO SUBTEND AN ANGLE OF FROM ABOUT 8 TO ABOUT 20 MINUTES, THE PORTIONS OFSAID CROSS LINES LYING WITHIN SAID CIRCLE HAVING A NATURAL LINETHICKNESS OF FROM ABOUT 25% TO ABOUT 50% OF THAT OF THE LINES OUTSIDE OFSAID CIRCLE.